So I've got my Trek 800 Sport that I've had since 2000. It's only got about 2 years use on it because it was in storage the rest of the time. It doesn't have the fancy shocks or suspension that the new bikes do, so should I upgrade or is this good enough?

What you have is fine. On the road you don't need suspension (adds weight - a LOT of weight) the 800 was/is a great bike. If you so desire, you can upgrade to an 8 speed and better brakes (Canit's or V brakes) for a lot les than a new bike.

__________________
"Whenever I see an adult riding a bicycle, I know there is hope for mankind." (H. G. Wells)